Automatic dishwashing compositions

ABSTRACT

A CLEANING COMPOSITION PARTICULARLY ADAPTED FOR WASHING DISHES, GLASSES AND SILVERWARE IN MECHANICAL DEVICES SUCH AS AUTOMATIC DISHWASHERS AND CAPABLE OF REDUCING SPOTTING AND FILMING THEREOF, CONTAINING AS THE ESSENTIAL INGREDIENTS ABOUT 1-20% SUCROSE, 0.5-5% HALIDE BLEACHING AGENT, AND 40-95% OF AT LEAST ONE WATER-SOLUBLE ORGANIC AND/OR INORGANIC BUILDER SALT.

United States Patent Office Patented Oct. 31, 1972 cumbersome, inconvenient and an added expense in the 3,701,735 use of automatic machine dishwashers.

AUTOMATIC DISHWASHING COMPOSITIONS Patricia A. Finck, Bayonne, N.J., assignor to Colgate- Palmolive Company, New York, NY.

No Drawing. Filed Apr. 12, 1971, Ser. No. 133,338

Int. Cl. Clld 7/18, 7/38 U.S. Cl. 252-99 9 Claims Accordingly, it has now been discovered that the inclus1on of a quantity of sucrose directly in the detergent formulation surprisingly effects a reduction in the spottlng and filming of tableware without adversely affecting its cleaning efiicacy, and completely eliminating the separate llIlSlIlg step heretofore found necessary. While the proportion of sucrose in a detergent formulation may be ABSTRACT OF THE DISCLOSURE 10 varied, a desirable range is from about 1% to by i weight of the total formulation, a preferred range being A f g OOmPQSIUOX} partlculafly for l from approximately 2% by weight to approximately 10% mg dishes, glasses and silverware in mechanical devices by weight of the total formulation such as automatic dishwashers and capable of reducing Thus, a primary object of the present invention resides spot lug and filmlng therwf, Contalnmg as essennal 15 in the provision of cleaning compositions capable of mgl'edlents about 140% Sucrose, hallde bleach providing essentially spot-free tableware. ing agent, and 40-9570 0? a least one water'soluble Another object of the present invention resides in the Orgamc and/01' lnorganlc builder Saltprovision of cleaning compositions capable of providing superior cleaning activity, eg bleaching, washing, etc. 0 Still another object of the present invention resides in The present lnventlon re t In genefifl. to cleanmg the provision of cleaning compositions capable of providcomposltions and in particular to the provision of cleaning essentiaqly fi1 f tab1eware mg compositions benefici lly p d use n comm Other objects and advantages of the present invention tlon W h the p film-free le of tablewarewill become more apparent'hereinafter as the description Many of the cleaning compositions heretofore recomproceeds mended for use in connection with the cleaning of tableware have been subject to one or more significant disadvantages. Perhaps the paramount difiiculty involved relates to the tendency of such compositions to leave undesirable spots and streaks on the washed tableware. As 'will be recognized, aesthetic considerations rather than purely functional criteria are often of overriding importance as regards the suitability of a given cleaning composition and especially when contemplated for use in connection with the cleaning of tableware. Without intending to be bound by any theory, it has nevertheless been hypothesized in explanation of the spotting and filming phenomenon that the presence of polyvalent metals such as calcium, magnesium, etc. normally found in tap water, precipitate out in the presence of the strongly alkaline cleaning solutions and deposit on the tableware. In addition, the presence of high food soil concentrations may cause excessive foaming, due to saponification of fatty food soils in the alkaline cleaning solutions, which interferes with the mechanical cleaning action by reducing the pressure at which the washing fluid is impelled against the tableware in the machine.

In an effort to overcome or otherwise ameliorate the foregoing and related difliculties, considerable research activity has been necessary in the development of cleaning compositions specifically and advantageously adapted to minimize the spotting and filming problem and yet capable of providing the requisite measure of cleaning activity. Thus, much of the methodology heretofere promulgated involves as an essential expedient the use of one or more additives which purportedly function as rinse additives in the final rinse as a separate and distinct operation in the mechanical washing of tableware. In this regard, a final and separate rinse has been recommended by the prior art after a clear water rinse (to rid the solution of the alkali found in the wash stage), which contain a water-soluble starch degradation product and/or sugar; or an ester of a sugar and a fatty acid; or a low foaming organic polyethenoxy non-ionic surfactant and a polyoxyalkylene glycol mixture; etc. Although a final rinse with a rinse additive has provided somewhat effective in overcoming the spotting and filming problem, the necessity of utilizing a separate rinse additive is In accordance with the present invention, a watersoluble alkaline detergent composition for automatic dishwashing comprises about 40-95% by weight of at least one water soluble organic and/or inorganic builder salt; about l-20% by weight sucrose, and about 0.5-5 by weight of a bleaching agent capable of releasing hypohalite in aqueous media.

The sucrose contemplated for use in the practice of the present invention and capable of substantially reducing both spotting and filming of tableware is watersoluble, and may be either fine or granulated. Sucrose is a. disaccharide composed of D-glucose and D-fructose, having the chemical formula C H O and also known as saccharose and saccharobiose. Commercially, sucrose is known as sugar, and is produced from cane sugar (ordinary table sugar), beet sugar, maple sugar, and sorghum sugar. The type and amount of sugar utilized is dependent on availability, cost and compatibility with the other ingredients of the detergent composition. However, the granulated form of sugar has been found preferable because of the ease with which it can be blended with the other ingredients. It has been found that amounts as low as 1% sucrose by weight are effective in obtaining superior inhibition of spotting and filming of tablewere washed in a mechanical dishwasher, although the preferred range is 2 to 10% by weight of the total detergent composition.

The wuter soluble builder salts utilized in the instant detergent composition comprises one or more inorganic and/or organic basic and neutral water soluble salts. The builder salts are employed in amounts ranging up to about 95%, i.e. 40-95% by weight with a range of from about 60% to about by weight of the composition being preferred. Suitable inorganic builders include without necessary limitation, trisodium phosphate, tetrasodium pyrophosphate, sodium acid pyrophosphate, sodium tripolyphosphate hexahydrate, sodium monobasic phosphate, sodium dibasic phosphate, sodium hexameta phosphate, sodium silicates, SiO /Na 0 of 1/1 to 3.2/1, e.g. (sodium metasilicate), sodium carbonate, sodium sulfate, borax, etc. Suitable organic builders include salts of organic acids and, in particular, the water soluble salts of aminopolycarboxylic acids and hydroxycarboxylic acids. The alkali metal salts such as sodium potassium and lithium; ammonium and substituted ammonium salts such as methylammonium, diethanolammonium and triethanolammonium; and amine salts such as mono, diand triethanolamine, methylamine, octylamino, diethylenetriamine, triethylenetetramine and ethylenediamine are efiicacious. The acid portion of the salt can be derived from acids such as nitrilodiacetic; N-(Z-hydroxyethyl) nitrilodiacetic acid, nitrilotriacetic acid (NTA), ethylenediamine tetracetic acid, (EDTA); N-(2-hydrooxyethyl) ethylenediamine triacetic acid; 2-hydroxyethyl iminodiacetic acid; l,2-diaminocyclohexanediacetic acid; diethylenetriamine penta-acetic acid, citric acid and the like. The builder salt is preferably employed in amounts sufficient to yield a pH in water of from 9.5 to 12 preferably from 10 to 11 in order to obtain optimum detergency performance.

The cleaning compositions described herein are further provided with one or more bleaching agents which may in general be defined as encompassing compounds capable of liberating a hypohalite such as hypochlorite chlorine and/or hypobromite bromine on contact with aqueous media. Particular examples of bleaching agents include the dry, particulate heterocyclic N-bromo and N- chloro imides such as trichlorocyanuric, tribromocyanuric acid, dibromoand dichlorocyanuric acid, the salts thereof with water-solubilizing cations such as potassium and sodium and mixtures thereof. Particular compounds found useful are potassium dichloroisocyanurate and trichloroisocyanuric acids.

Other N-bromo and N-chloro imides may also be used, such as N-brominated and N-chlorinated succinimide, malonimide phthalimide and naphthalimide. Other compounds include the hydantoins, such as 1,3-dibromo and 1,3-dichloro-5,5-dimethylhydantoin; N monochloro-5,5- dimethylhydantoin, methylene bis(N bromo 5,5 dimethylhydantoin); l,3-dibromo and 1,3-dichloro-S-isobutylhydantoin; 1,3-bromo and 1,3-dichloro, -methyl-5- n-amylhydantoin, and the like. Other useful hypohaliteliberating agents comprise tribromomelamine and trichloromelamine. Dry, particulate, water soluble anhydrous inorganic salts are likewise suitable for use such as lithium hypochlorite and hypobromite. The hypohaliteliberating agent may, if desired, be provided in the form of a stable, solid complex or hydrate, such as sodium ptoluene-sulfo bromamine trihydrate, sodium benzenesulfo-chloramine-dihydrate, calcium hypobromite tetrahydrate, calcium hypochlorite tetrahydrate etc. Brominated and chlorinated trisodium phosphate formed by the reaction of the corresponding sodium hypohalite solution with trisodium phosphate (and Water as necessary) likewise comprise efiicacious materials. The present invention contemplates as an additional embodiment the use of bleaching agents capable of liberating hypochlorite as well as hypobromite such as, for example, the N- brominated, N-ch1orinated heterocyclic imides, as for example the N-bromo, N'-chlorocyanuric acids and salts thereof, e.g., N-monobromo-N, N-dichloro-cyanuric acid, N-mono-bromo-N-monochlorocyanuric acid, sodium-N monobromo N monochloroeyanurate, potassium .N- monobromo-N-monochlorocyanurate; and the N-brominated, N-chloronated hydantoins, e.g., N-bromoN-chloro- 5,5-dimethylhydantoin and N-bromo-N-chloro-S-ethyl-S- methyl hydantoin.

The hypohalite-liberating compound is employed in an amount of from 0.5 to 5% by weight of the composition, and preferably in an amount of from about 0.5 to 3% by weight thereof. In any event, the hypohalide material should preferably be employed in amounts sufficient to yield from about 0.5-3% available chlorine, bromine etc. in order to assure optimum results.

Water soluble organic detergents, i.e. surface active components may be employed, such materials bein well known in the prior art, the term detergent comprehending species of the anionic, cationic, amphoteric and zwitterionic types. In formulating an automatic dishwasher product, it is preferred to utilize a low foaming detergent such as the non-ionics.

Nonionic surface active agents include those surface active or detergent compounds which contain an organic hydrophobic group and a hydrophilic group which is a reaction product of a solubilizing group such as carboxylate, hydroxyl, amido or amino with ethylene oxide or with the polyhydration product thereof, polyethylene glycol.

As examples of nonionic surface active agents which may be used there may be noted the condensation products of alkyl phenols with ethylene oxide, e.g., the reaction product of isooctyl phenol with about 6 to 30 ethylene oxide units; condensation products of alkyl thiophenols with 10 to 15 ethylene oxide units; condensation products of higher fatty alcohols of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate, sorbitol mono-oleate and mannitan monopalmitate, and the condensation products of polypropylene glycol with ethylene oxide.

Further suitable detergents are polyoxyalkene esters of organic acids, such as the higher fatty acids, rosin acids, tall oil, or acids from the oxidation of petroleum, and the like. The polyglycol esters will usually contain from about 8 to about 30 moles of ethylene oxide or its equivalent and about 8 to 22 carbon atoms in the acyl group. Suitable products are refined tall oil condensed with 16 or 20 ethylene oxide groups, or similar polyglycol esters of lauric, stearic, oleic and like acids.

Additional suitable non-ionic detergents are the polyalkylene oxide condensates with higher fatty acid amides, such as the higher fatty acid primary amides and higher fatty acid monoand di-ethanol amides. Suitable agents are coconut fatty acid amide condensed with about 10 to 30 moles of ethylene oxide. The fatty acyl group will similarly have about 8 to 22 carbon atoms, usually about 10 to 18 carbon atoms in each product. The corresponding sulphonamides may also be used if desired.

Other suitable polyether non-ionic detergents are the polyalkylene oxide ethers of higher aliphatic alcohols. Suitable alcohols are those having a hydrophobic character, and preferably 8 to 22 carbon atoms. Examples thereof are iso-octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl and oleyl alcohols which may be condensed with an appropriate amount of ethylene oxide, such as at least about 6, and preferably about 10-30 moles. A typical product is tridecyl alcohol, produced by the 0x0 process, condensed with about 12, 15 or 20 moles of ethylene oxide. The corresponding higher alkyl mercaptans or thioalcohols condensed with ethylene oxide are also suitable for use in compositions of the present invention.

Examples of other suitable wetting agents include low foaming anionic materials such as dodecyl hydrogen phosphate, methyl naphthalene sulfonate, sodium Z-acetamidohexadecane-l-sulfonatc, and mixtures thereof. Mixtures of the foregoing wetting agents may also be employed, and, if desired, foam-reducing additive may be added as appropriate to minimize undesirable foaming tendencies of these wetting agents under conditions of use.

The detergent material is employed in concentrations ranging from about 0.5% to about 5% by weight of total composition with a range of 1% to 3% being particularly preferred.

Thus, a relatively minor amount of nonionic type de tergent, that is, about 24% is especially beneficial inasmuch as it acts as a a foam depressant as well as a detersive agent in an automatic dishwashing solution.

Minor amounts of other additives which do not inter= fere with the cleaning properties of instant composition may be added such as pigments, dyes, perfume, fillers,

extenders, suds builders, suds depressors, anti-redeposition agents, polyelectrolytes which function as soil suspending and/or peptizing agents including polycarboxylates, polyaminomethylphosphonate, maleic anhydride-acrylic acid polymer, starch degradation products, polymethyl vinyl ether/maleic acid, and the like, overglaze protectors including aluminum acetate, aluminum formate, sodium and aluminum phosphate, alkali aluminate, zincate, berylliate, perfumes, boric oxide, boric anhydride, etc. In some instances it may be commercially feasible to add said ingredients to render them more attractive to the consumer.

The following examples are given for purposes of illustration only and are not to be considered as necessarily constituting a limitation on the present invention. All parts and percentages given are by Weight unless otherwise indicated. For purposes of ascertaining the capacity of the various compositions exemplified to reduce spotting and filming of tableware, the method of the Chemical Specialties Manufacturers Association (CSMA) is employed, such method being described in detail in Soap and Chemical Specialties, 33 (9), 60, 1957. This method is modified for testing formulations for use in dishwashers to show spotting and film build-up on glass tumblers and/or photographic plates in the presence of a standard soil comprising 80% margarine and 20% Starlac by equally loading a dishwasher with five glass tumblers and live photographic plates on the upper rack and six large dinner plates plus smaller plates on the bottom rack; adding the standard soil to the dishwashers; placing 30 grams of detergent in each cup for a 0.3% concentration; introducing tap water at 140 F. and running the machine through a complete cycle. The contents are cooled to 75 F. and visually rated in the presence of good light in accordance with the following scale:

. Glass spotless or film-free Spots at random or barely perceptible film A of glass covered with spots or apparent film /2 glass covered with spots or moderate film Glass completely covered with spots or heavy film Utensils of stainless steel, silverware, copperware and aluminum ware may also be included for testing purposes.

The following examples are given for purposes of illustration only and are not to be considered as limiting the present invention. All parts and percentages are by Weight unless otherwise indicated. The compositions are prepared usually by dry-blending the ingredients to form a dry, particulate product such as a free-flowing granular composition or powder.

EXAMPLE 1 This example illustrates the applicability of the present invention to the preparation and use of cleaning compositions specifically adapted for use in connection with dishwashing operations. The following composition is prepared:

Ingredients: Percent Sodium tripolyphosphate hexahydrate 64.45 Sodium metasilicate, anhydrous 20.0 Sodium sulfate, anhydrous 5.63 Nnon-ionic detergent 1.5 Color 0.10 Water 0.30 Perfume 0.02 Potassium dichloroisocyanurate 2.0 Sucrose 6.0

The non-ionic detergent is the product obtained by the condensation of about three mols of propylene oxide with the condensation product of one mole of a mixture of essentially straight chain, primary, fatty alcohols in the Cm-C18 range with about six mols of ethylene oxide.

Results of evaluations of the tableware are tabulated below as an average of four washes. (Rating scale: 1-no spotting or filming to 5heavy spotting or filming). The bleach-no sugar formula is a control wherein the 6% sucrose is replaced by additional amounts of 2% of said phosphate and 4% sulfate.

As the above data makes manifestly clear, instant formulation provides essentially spotand film-free tableware, inclusive of stainless steel, silverware, copperware and aluminum ware in addition to glass tumblers and plates. This same composition without the sugar exhibited spotting, filming and discoloration of aluminum ware, copperware, silverware and stainless steel as well as spotting and filming of glassware.

EXAMPLE 2 Ingredients: Percent Sodium tripolyphosphate hexahydrate 61.5 Sodium metasilicate, anhydrous 20.0 Sodium sulfate, anhydrous 5.6 Non-ionic detergents-Ex. 1 1.9 Potassiumdichloroisocyanurate 2.0 Sucrose 6.0

Sodium acid aluminum phosphate (overglaze protector) 3.0

In addition to yielding spot and film free tableware, this composition exhibited superior overglaze protection when the sucrose is present, i.e., a synergistic effect in overglaze protection of fine china is produced by the combination of overglaze protecting agent and sucrose.

EXAMPLE 3 Example 2 is repeated except that the sodium acid alummum phosphate is omitted and 6% boric anhydride added and the sodium sulfate reduced to 2.6%. The results obtained are similar to those of Example 2.

EXAMPLE 4 Example 2 is repeated except that 6% boric anhydride 18 added and the sodium sulfate is omitted and the phosphate content reduced to 61.1%.

EXAMPLE 5 Example 2 is repeated, but 3% boric anhydride is added and the sodium sulfate is reduced to 2.6%.

EXAMPLE 6 Ingredients: Percent Sodium citrate.2H O 45.0 Non-ionic detergent-Ex. 1 2.0 Potassium dichloroisocyanurate, granular 2.0 Sucrose 6.0 Sodium metasilicate, anhydrous, granular 10.0 Sodium carbonate, light granular 20.0 Sodium sulfate, anhydrous 8.35 Boric acid 3.0 Boric oxide 3.0 Polyamino methyl phosphonate 1 0.5 Perfume 0.15

1 Obtained from Monsanto.

EXAMPLE 7 Ingredients: Percent Sodium nitrilotriacetate -a 35.0 Sodium ethylene-diaminetetracetate 2.0 Polyamino methyl phosphonate 0.5 Potassium dichloroisocyan'urate 1.5 Non-ionic detergentEx. 1 2.0 Sucrose 6.0 Sodium acid aluminum phosphate 3.0 Soda ash 35.0 Sodium sulfate, anhydrous 15.0

EXAMPLE 8 Ingredients: Percent Anhydrous sodium metasilicate 15.0 Anhydrous sodium sulfate 11.0 Non-ionic detergent-Ex. 1 2.0 Potassium dichloroisocyanurate 1.0 Trisodium nitriloacetic acid 40.0 Sodium citrate dihydrate 25.0 Sucrose 6.0

The above formulations yield essentially spot and film free tableware, irregardless of the type of builder salt or salts present; said superior results being a function of the combination of the bleach and sucrose components in the presence of the highl alkaline medium. Variations in the amount of sucrose in the above type formula such as 2% and 9% sucrose, etc., yield highly satisfactory results also.

When the foregoing procedure is repeated by the sucrose omitted, undesirable spotting and filming is clearly evident. When the amount of sucrose is increased substantially such as to about 70% with a corresponding decrease in the amount of builder salts, then the level of spotting and filming of tableware becomes unacceptable, with greater spotting and filming in waters of increasing hardness.

In addition, the exemplified procedure make unavoidably clear that the compositions provided in accordance with the present invention are capable of superior cleaning activity i.e., displaying an outstanding capacity to readily remove stain deposits from a wide variety of glazed dishware and aluminum ware, without generally adversely affecting said glazed surfaces.

Effective industrial bottle cleaning compositions may be provided in accordance with the present invention by merely admixing with caustic alkali whereby to provide a highly alkaline composition preferably having a pH of about 12. Such compositions may be readily formulated in accordance with the parameters hereinbefore described.

Results similar to those described in the foregoing examples are obtained when the procedures delineated there in are repeated but employing in lieu of the specific nonionic detergent identified a variety of materials selected from low-foaming nonionic, anionic, cationic, amphoteric and zwitterionic types. Moreover, various bleaching agents hereinbefore recommended for such purposes may be readily employed to advantage. Similarly, any water soluble salt or combination of salts can be advantageously used inclusive of the organic and/or inorganic salts.

While the detergent composition of the present invention finds most efiicacious utilization in connection with the washing of the dishes and the like in automatic dishwashers, naturally, the detergent may be utilized in other fashions as desired. Usually, however, the best mode of use will be in connection with automatic dishwashers which have the ability of dispensing the detergent of the present invention in one or more separate wash cycles. Accordingly, the detergent compositions of the present invention is added to the two receptacles, if such are present, in an automatic dishwasher. When the dishwasher is set 1nto operation, after the dishes have been suitably posltioned therein, the automatic devices of the dishwasher permit the addition of sufficient water to produce a concentration of the detergent composition of approximately 0.15 to 0.5 by weight. The operation of the dishwasher results In treating, that is, washing of the dishes with the aqueous solution of the detergent composition. Usually, the sequence of operation in utilizing an automatic dishwasher results in one or more rinsing steps following the one or more washing cycles. In utilizing the detergent composition of the present invention it will be noted that the tableware is substantially spotand film-free without resorting to a separate and distinct final rinse with rinsing aids. In addition, these detergent compositions are substantially non-corrosive to the overglaze on china and to aluminum ware.

It will be apparent that many changes and modifications of the several features described herein may be made without departing from the spirit and scope of the invention. It is therefore apparent that the foregoing description is by way of illustration of the invention rather than limitation of the invention.

What is claimed:

1 A water-soluble alkaline dishwasher detergent composition capable of substantially reducing the spotting and filming of tableware consisting essentially of about 40-95% by weight of at least one water-soluble organic and/or inorganic basic or neutral builder salt; about 1-20% by weight of sucrose; and 0.5-5.0% by Weight of a bleaching agent capable of releasing hypochlorite or hypobromite in an aqueous media.

2. A composition in accordance with claim 2, which also includes about 0.5 to 5% by weight of a water-soluble low-foaming non-ionic organic detergent.

3. A composition in accordance with claim 2, wherein the organic detergent constitutes l3% by weight of a non-ionic ethoxylated alcohol surfactant.

4. A composition in accordance with claim 3, wherein the bleaching agent is potassium dichloroisocyanurate.

5. A composition in accordance with claim 1, which also includes an overglaze protector.

6. A composition in accordance with claim 1, wherein the builder salt is sodium citrate.

7. A method for treating glasses, dishes and tableware to remove foreign bodies from the surfaces thereof in a spot and film-free condition comprising treating said tableware with a dilute aqueous solution of the composition defined in claim 1.

8. A method of cleaning tableware by washing with an aqueous solution of the composition defined by claim 6.

9. A method of safely cleaning fine china and other tableware by washing with an aqueous solution of the composition defined in claim 5.

References Cited UNITED STATES PATENTS 3,494,868 2/1970 Gray 252-99 MAYER WEINBLATT, Primary Examiner 

